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A Study on Modifying the Calculation Model of valid Opening Size of Heat-bonded Nonwoven Fabrics

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Journal of China Textile University(English Edition) 1999年第3期16卷 52-56页

作者：余序芬吴美萍

It has been found that there are marked errors in the value of valid opening size of heat-bonded nonwoven fabrics between theoretical calculations and engineering measurements. A new modified theoretical model is advanced in this paper. The equivalent diameter of the pore of a fibre web is used to calculate the valid opening size instead of the maximum diameter of inscribed circle used, because the fibres in practical fibre webs are flexible elastomers with definite diameters and the pore of fibre web may produce deformation in screening teat and engineering usage. The results show that the theoretical calculations coincide well with the engineering measurements. This method offers a theoretical basis for computer simulation to the performance of filters of heatbonded nonwoven fabrics.

关键词： heat - bonded nonwoven fabrics theoretical model valid opening size model modification .

FOXPRO 命令中可选项 valid 的使用

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西安公路交通大学学报 1997年第2期17卷 124-126页

作者：孔庆芸西安公路交通大学计算机系

介绍了ＦＯＸＰＲＯ命令中可选项ＶＡＬＩＤ的格式及功能，并编写了若干程序实例。

关键词： FOXPRO valid 功能使用程序设计

FOXPRO有效性确定子句valid的设计

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中国金融电脑 1994年第5期 6-9页

作者：罗辉工商银行湖南省双峰县支行

ＦＯＸＰＲＯ有效性确定子句ＶＡＬＩＤ的设计工商银行湖南省双峰县支行罗辉ＦＯＸＰＲＯ数据库管理系统较之ＦＯＸＢＡＳＥ＋在功能上有了飞跃的改进或增强。在软件设计的具体编程中，感触最深之一是ＦＯＸＰＲＯ的全屏幕设计命令＠…... 详细信息

ＦＯＸＰＲＯ有效性确定子句ＶＡＬＩＤ的设计工商银行湖南省双峰县支行罗辉ＦＯＸＰＲＯ数据库管理系统较之ＦＯＸＢＡＳＥ＋在功能上有了飞跃的改进或增强。在软件设计的具体编程中，感触最深之一是ＦＯＸＰＲＯ的全屏幕设计命令＠…ＳＡＹ…ＧＥＴ的功能强大的ＷＨＥＮ...

关键词： FOXPRO valid 数据库管理系统湖南省双峰县工商银行帮助信息热键在线帮助数据输入数据库结构

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数据录入合法性检验语句valid的活用

电脑爱好者 1996年第6期 30-30页

作者：马季蚌埠市安徽财贸学院计算中心 233041

在@…GET语句中有四个与数据格式和数据合法性相关的子句,它们是:PICTURE、FUNCTION、RANGE和valid,前三者在使用时必须按规定形式和符号描述数据的输入输出格式、类型和范围,而valid子句的内容为一逻辑表达式,故而它在程序中的应用就... 详细信息

在@…GET语句中有四个与数据格式和数据合法性相关的子句,它们是:PICTURE、FUNCTION、RANGE和valid,前三者在使用时必须按规定形式和符号描述数据的输入输出格式、类型和范围,而valid子句的内容为一逻辑表达式,故而它在程序中的应用就较为灵活。valid子句的逻辑表达式,可以是直接与当前录入数据相关的表达式,也可是用户自定义的函数组成,如果该逻辑表达式的值为真,该项输入被认为是正确的,结束该项输入;如果该逻辑表达式的值为假,该项输入则被认为是不正确的,要求用户重新输入数据,这一过程直到逻辑表达式的值为真或用户按下Esc键为止,正是由于可以在逻辑表达式中使用用户自定义函数,使得我们能对数据的录入及合法性检验实施更为有利的手段,事实上,恰当地运用这种方法,不仅能完成某种特殊的任务,甚至在一定的程

关键词：逻辑表达式 valid 语句用户自定义函数 JE

Comparison study of two criteria for identification of structural dynamic stability

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Science China(Technological Sciences) 2019年第5期62卷 856-867页

作者： ZHOU Hao LI Jie School of Civil Engineering Tongji University State Key Laboratory of Disaster Reduction in Civil Engineering

Dynamic stability analyses of structures are becoming increasing prevalent in applications for tall buildings and space structure designs. This paper presents an effective energy criterion for identifying the dynamic stability of generalized structures through the modification of an earlier developed energy criterion for hardening structures. Two time-varying effective energy indices are introduced to account for the dynamic stability of both the hardening and deteriorating structures; one for the description of structural properties, i.e., the structural effective intrinsic energy, and the other for the measurement of the input energy, i.e., the valid external work. It is shown that a structure's stability can survive provided the effective intrinsic energy is always less than the valid external work during a dynamic excitation. The first passage of the effective intrinsic energy over the valid external work indicates the dynamic instability of the structure. A comparison study is carried out regarding the validity and applicability between the energy and effective energy criteria as applied to the dynamic stability analysis of three different structures.

关键词： identification criterion dynamic stability effective intrinsic energy valid external work deteriorating structure

A metaheuristic method for the multireturn-to-depot petrol truck routing problem with time windows

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Petroleum Science 2019年第3期16卷 701-712页

作者： Bohong Wang Yongtu Liang Meng Yuan Haoran Zhang Qi Liao National Engineering Laboratory for Pipeline Safety/Beijing Key Laboratory of Urban Oil and Gas Distribution Technology China University of Petroleum

The petrol truck routing problem is an important part of the petrol supply *** study focuses on determining routes for distributing petrol products from a depot to petrol stations with the objective of minimizing the total travel cost and the fixed cost required to use the *** propose a mathematical model that considers petrol trucks returning to a depot multiple times and develop a heuristic algorithm based on a local branch-and-bound search with a tabu list and the Metropolis acceptance *** addition,an approach that accelerates the solution process by adding several valid inequalities is *** this study,the trucks are homogeneous and have two compartments,and each truck can execute at most three tasks *** sales company arranges the transfer amount and the time windows for each *** performance of the proposed algorithm is evaluated by comparing its results with the optimal *** addition,a real-world case of routing petrol trucks in Beijing is studied to demonstrate the effectiveness of the proposed approach.

关键词： Petrol truck routing problem Heuristic algorithm valid inequalities Time windows

THE EXISTENCE AND UNIQUENESS THEOREMS OF THE LINEAR AND NONLINEAR RIEMANNHILBERT PROBLEMS FOR THE GENERALIZED HOLOMORPHIC VECTOR OF THE SECOND KIND

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Acta Mathematica Scientia 1990年第2期10卷 185-199页

作者：黄烈德 Tongji Univ. Shanghai China

In this paper, the existence and uniquenss theorems are proved for the linear and nonlinear Riemann-Hilbert problems for the generalized holomorphic vector of the second kind.

关键词： inequality kernel singular Riemann 介公二尹 valid satisfy 七印柳万

Behavior of steel-concrete composite slabs subjected to standard fire

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Journal of Harbin Institute of Technology(New Series) 2002年第2期9卷 155-160页

作者：毛小勇张耀春韩林海 Sch. of Civil Eng. Harbin Inst. of Technol. Harbin 150001 China

Finite element method is employed to calculate the temperature fields for two kinds of steel concrete composite slabs: composite slab with profiled steel sheeting and LJMB composite slab. The calculated results are in good agreement with those of tests. Fire resistance of the two kinds of composite slabs is calculated by using a numeric method. The results show that: due to heat absorbing of concrete, the performance of composite slabs under fire is better than that of unprotected steel structure, and fire resistance of composite slabs mentioned in this paper is at least 30 min subjected to standard fire. Parameters related to the fire resistance are discussed. It was found that with increasing of concrete strength and thickness of slab, fire resistance increases, and with increasing of steel strength and steel ratio, fire resistance decreases. Also thickness of fire proof is calculated by a numeric method. The results obtained in this paper may be referenced for practical engineering.

关键词： Composite slab temperature fields valid load under fire failure criteria fire resistance fire proof finite element numeric method

ON n- WIDTHS OF PERIODIC FUNCTIONS

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Chinese Annals of Mathematics,Series B 1991年第3期12卷 272-281页

作者：陈翰麟 Institute of Mathematics Academia Sinica Beijing China.

Let r,1p={f:fr-1 is abs. cont. on I=[a, b], f is periodie with period H（=b-a）,f（x1）=0,‖f（r）‖p≤0}, where x1 is any fixed point in [a, b]. The author finds the Kolmogorov, Gel’land, linear, and Berustein n-wid... 详细信息

关键词： operators Kolmogorov proof hereby valued 加名 normed 弘一万石 valid